Absorption refrigerating apparatus



Oct. 29, 1935. K. HHNEL 2,019,409

` ABSORPTION REFRIGERATING APPARATUS D o o o I O l I i I o`\ Oo .Y

l] o o o o o Oct. 29, 1935. K. HHNEL ABSORPTION REFRIGERATING AYPARATUS Filed July 9, 1954 2 Sheets-Sheet 2 Patented Oct. 29, 1935 ABSORPTION REFRIGERATING APPARATUS Kurt Hhnel, Berlin-Siemensstadt, Germany, asslgnor to Siemens-Schuckertwerke Aktiengesellschaft, Berlln-Siemensstadt, Germany, a corporation of Germany Application July 9, 1934, Serial No. 734,388 In Germany July 14, 1933 12 Claims.

My invention relates to improvements in absorption refrigerating apparatus of the intermittent type and more particularly to improvements in heat control devices therefor.

Systems for regulating the heat required for the operation of absorption refrigerating lapparatus' of theintermittent type are well known. One of the simplest ways of attaining this aim consists in employing a time-control switch inserted in the heating circuit of the generatorabsorber. 'I'his clock switch is so set as to energize the heating device for a predetermined period and to deenergize the same for a predetermined period. When employing electrically heatl5 edV absorption refrigeratng apparatus in .connection with such heat control devices disadvantages are presented in that the energy input to the heating element depends to a great extent upon the uctuations of voltage resulting in the .YJ n supplyA circuit.

In other heat control systems hitherto known thermostats are employed operating in accordance with the temperature prevailing in the absorption refrigerating apparatus for energizing Z-.- and deenergizing the heating element. The ther-- mostats, for instance operate in accordance with the temperature prevailing in the generator-absorber and evaporator. The various heat control systems of the above-indicated character 33'. hitherto employed may be readily adapted in operation to the outer operating conditions (temrefrigeration and the like). By-the use of such thermostats it is in most cases necessary to eiect 3`5` the switching operation at great diierencesof temperature. For instance, it is required that the thermostat operating in accordance with the temperature prevailing in the generator-absorber be deenergized at 130 and energized at 40 C.

0 Thermostats of this type encounter great diculties in manufacturing-the same and are not reliable in operation; The object ofthe present invention is to pro.- vide a heat control device for absorption refrig- 5 erating apparatus of the intermittent type.'

whereby the diiiculties encountered in the heatcontrol systems hitherto known are removed. To this end a counting mechanism (gas or kilowatt hour meter) is inserted in the heating circuit which causes the heating agent to be cut oi after if l a predetermined amount of the heating Power has been supplied. In order to obtain a simple and eflicient system the energy input oi the heating element is adjusted to the optimum value of "1 the reirigerating apparatus under consideration.

perature of the refrigerant. required amount ofv The control of the heat supply is eilected according to the invention by adjusting the counter mechanism in such a manner as to supply the generator with a smaller or greater amount oi heat energy without thereby impairing the efl flciency of the-system, whereas in the heating systems hitherto known operating with a given number of heat regulating ranges the eiiiclency of these systems is impaired when passing from the normal heat regulatingrange to the ranges corl0 be also controlled by thermostats which regulate the temperature prevailing in the evaporator and generator-absorber. In this case the heating element is energized upon an increase in' temperature in the evaporator above a predetermined value and upon a decrease oi' the temperature in the generator-absorber below a predetermined value, while the counting mechanism prof vides for the proper heat input.

After the energization of the heating element lo the counting mechanism determines the duration of the heating period. It switches oil the heating agent directly or indirectly after a predetermined A adjusted amount of energy has been consumed. The clockwork reenergizesi the heating element $5 after a predetermined period. The reenergization of the heating system is besides preferably controlled byl a thermostat which is arranged in the cooling chamber itself or in contact with the cold producing parts of the absorption refrigerating 4o apparatus. This thermostat-interrupts the circuit upon a .decrease of the temperature below a predetermined value and prevents the energize.- tion of the heating element of the generator till the temperature increases above a predetermined value. In this manner a device is obtained which may be easily adapted to the iluctuating operating conditions.

In the accompanying drawings some embodiments of my invention are illustrated in diagrammatical form.

Fig. l shows an embodiment of my invention as applied to a domestic refrigerator which is equipped with an air-cooled absorption refrigerating apparatus of the intermittent type.

der possible an abrupt interruption of the heating circuit.

Flg. 2 shows a detail of a switching mechanism for elnergizing and deenergizing the heating elemen Fig. 3 shows details oi switching mechanisms according to my invention.

Eig. 4 shows a modified form of my invention Fig. 5 shows an embodiment of an electrically operated tilting switch according to my invention for energizing and deenergizing the heating element of the generator.

Referring to Fig. 1, I denotes the generatorabsorber charged with solid chemical absorbents, for instance calcium-chloride. The generatorabsorber is heated by an electric heating element 2 disposed within the same. During the heating period the refrigerant (for instance ammonia) is driven oil from the generator-absorber I and passes into an air-cooled condenser 2 whence it passes into an intermediate container 4 arranged in the insulation of the refrigerator. An evaporator coil 5 disposed in a cold accumulator 2 is connected to the container 4. The accumulator projects into the cooling chamber 'I as shown in Fig. 1. During the absorption period the liquid refrigerant contained in the evaporator is again evaporated and ilows back into the generatorabsorber where it is reabsorbed by the solid absorbents. To effect a good dissipation of the heat of absorption cooling ribs 8 are arranged on the outer wall of the generator-absorber.

In order to energize the heating element a switching disc I0 driven by a clockwork 9 is p'rovided. The disc I0 carries three switching pins I I distributed as disclosed in Fig. l over the periphery of the disc I0.

To insert the switching pins II in the disc I0, the latter is preferably provided with a relatively large number of holes so that the time of the energizing impulses and the spaced interval between two energizing impulses may be varied at will.

The switching disc I0 makes in the present case a complete revolution within 24 hours, so that three impulses are transmitted in the course of 24 hours by the three switching pins. Theheating energy is supplied by a supply circuit I2, I2. A switch I4 serves to energize and deenergize the heatingA element 2, the switch being rotatably mounted as shown at I5. 'A spring I8 is attached to the upper part of the switch and firmly fixed as shown at I1. The lever switch I4 is provided with a movable contact I9 which in the position shown in the drawings engages the elastically designed stationary counter contacts 20, thus closing the heating circuit.

VBy closing the heating circuit a kilowatt hour meter 2| is operated which drives a second switching disc 22 in clockwise direction. The disc 22 carries a switching pin 22 which cooperates with the upper free end of theswitch I4. 'Ihe duration of the heating is preferably determined by a complete rotation of the switching disc 22. There are also cases in which 1/2, $4, or 1;/8 of a revolution are desirable. Afterthe switching disc 22 has made a complete revolution, the switching pin 23 brings the switch I4 into the switching position shown in dotted lines, thus .interrupting the heating circuit. The spring I8 serves to ren- Between the counting mechanism 2I and the switching disc 22 a transmission gear 24 is provided by means of which the duration of the heating period may be adjusted. Since in the presentcase itis intended tooperate with the optimum takento eliminate the blocking 0f the switch Il by the switching pin 22 upon the reenergization of the heating element. .The switching pin 22 is, therefore, not rigidly xed to the disc 22 but is m connected with the disc 22 by means of a spring 5I. Further a stop 521s arranged on the dise 22 and serves to prevent the movement o! the switching pin 22 to the right but does not prevent, how- 'ever, the lever I4 from moving. Upon the rota- 15 tion of the disc 22 the` switching pin 22 engages at iirst the upper end of the lever I4. The disc 22 rotates under the. tension of the spring 5I until the stop 52 takes valong the switching pin 22. 'lhe latter rotates the switching lever I4 to such an 20 extent that it snaps over in the other switch position when surpassing the. unstable position of equilibrium. At this moment the switching pin 22 is brought away from the stop 52 'under the action of the spring 5I into the position shownin 25 dotted lines, so that it ds not prevent the movement of the switching lever I4 when springing backwards.

Another modiilcationV of the switch shown in Fig. 1 with which the blocking of the switch I4 30 effected by the switching pin 22 is eliminated is shown in Fig. 2. In this embodiment the switching pin 22 is rigidly connected to the disc 22.

. The upper end of the switching lever I4 is provided in this case with a lever 54 rotatably 35 mounted as shown at 52, which is brought into the position shown in the drawings by a spring 55. If the rswitching pin 22 owing to the, rotation of the disc 22 engages the lever 54 the latter is brought under the tension of the spring 25 into a the position shown in dotted lines by the switching pin 22. The lever 54 is rotatably mounted in a fork-shaped upper end of the switch I4. so as not to pass beyond the position shown in dotted lines. Upon further rotation of the disc 22 the switching pin 22 brings the switchv I4 beyond the unstable position, so that it tips over into the other switch position. Consequently. the lever 54 is free to move and is brought under the-action of the spring 55 into such a position that it may be caused to pass the switching pin 22 at rest without touching it upon the snapping back of the switch I4.

To control the temperature in the cooling chamber a thermostat 25 is provided which il u arranged in the cold storage tank 6. The thermostat 25 locks the heating circuit so long as the temperature in the cooling chamber, lies below `a predetermined value. As soon as the thermostat causes the energization of the heating eleno ment the next following heatingperiod may be initiated, if the time adjusted on the disc Il between the energization and deenergization o! the heating element has at least elapsed. If the switching disc I Il has already closed the contacts o5 I9 and 2|! the energization of the heating elehowever, initiate a new heating period already after two and a half hours. 'Ihis would be, however, too soon, since the reserve of refrigerant which has been expelled shortly before would not be consumed. For this reason it is advisable to eliminate the action of the next following switching pin of the disc I 0 in case the heating takes i place too late. This may be attained in a simple manner by causing a brake controlled by the thermostat 25 to act upon'the shaft between the clockwork 9 and the switching disc I6. -The brake stops the clockwork 9 and the switching disc I0 as long as the thermostat interrupts the circuit. An arrangement which operates without stopping the clockwork 9 is shown in Fig. 3. The switching disc I6 is released from the clockwork 9 upon the switching in of the switch I4 by one of the switching pins II or shortly afterwards by a coupling 56. An electromagnet 51 whichis series-connected with the contacts 20 bridged by the switch I4 serves to actuate they coupling 56. If the eiectromagnet 51 is energized it moves the lever 58 in opposite direction to the action of a spring 59 so that the coupling 56 is switched in by means of the bell crank lever 69. A switching disc 6I, which is provided with notches 62, is firmly arranged on the disc I6 so that the upper end 63 of the lever 58 engages as shown in Fig. 3 one of the notches. The disc I6, consequently, rotates only when the switch I4 has been thrown into the position shown.

Consequently, the disc rotates from the beginning of the heating period in the present case,-

for instance, for eight hours before the .next switching pin may eiect a switching operation. If it is desired to operate the system with cheap night current a locking switch which is also actuated by the clockwork 9 should be inserted in the circuit.

The operation of the lever 58 may be also effected directly byl a thermostat which upon changes in temperature adjusts a bellows. Such an arrangement is particularly in use in systems operating with gas heating.

The construction shown in Fig. 4 operates according to the tariffs fixed by public utilities.

Fig. 4 shows a side elevation of a switching disc I8 which is actuated by a clockwork (not shown) through the shaft 66 firmly secured to the disc I9. This switching disc I0 may, for instance, be employed for energizing the heating element of the generator in a control device as shown in Fig. l. For the sake of simplicity only those parts cooperating directly with the switching disc I6 are illustrated in Fig. 4, i. e., only the lower end of the pivotally mounted switch I4 of Fig. 1 and the switching disc I 0 of the device serving to energize and deenergize the heating element. The switching pins II are movably arranged in the disc IIJ `so as to prevent themunder certain conditions from cooperating with the lower end of the switch I4.r To this end,v a lever 65 provided with a fork 64 engaging the pins I I is so pivotally mounted as indicated at 1I as to move the pins in the outward direction, thus bringing the latter out of contact with the lower end of the switching lever I4. While the switching disc I6 is rmly connected to the axis 1I a slidably mounted switching disc 61 is mounted on the same shaft, the disc 61 being xed to the switching disc I0 as shown in Fig` 1 by means of the spring 68. In this embodiment the switching pins II are brought into the 'switch position vshown at the desired time. The switching disc 61 is connected in a similar manner as shown in Fig. 3, for instance, by switching in the heating current with the aid of a magnet withv the \disc IIIby means of the coupling 69. Besides,

the coupling 69 during this operation also moves 5 the switching disc 61 to the right so that the .dishshaped portion 10 presses against the free ends of the lever 65 and raises, consequently, the three switching pins II, thus preventing them from switching in the switch I4 until the eight hours 10 for which the switching disc 61 has been set have elapsed, until the lever 58 shown in Fig. 3 comes to rest and until the coupling disengages and then again sets free the switching pins in the switching position. Consequently, the next 16 switching pin is prepared for the switching in. Fig. 5 shows an embodiment of my invention in which the energizing and deenergizing impulses are transmitted. electromagnetically through a tilting switch. The same numerals of Fig. 1 denote corresponding parts of Fig. 5. A tilting switch 26 serves to switch in and out the heating current. In the switch position shown the heating circuit is interrupted. 29 is a clockwork conlnected to the supply circuit and drives a switching disc 30 so that it makes a complete rotation within 24 hours. The switching disc 36 consists of insulating material and has three contacts 3i spaced at equal intervals on the periphery, the contacts being directly connected to the positive 30 pole of the supply circuit. A stationary counter contact 32 cooperates with the contacts 3|. As ysoon as one of the contacts 3| engages the contact 32 the coil of the magnet 33 of the tilting switch is energized so that the latter is tilted into $5 the other switch position, thus closing the heating circuit at its contact 21. By the closure oi the contacts 21 the kilowatt hour meter 26 is Y also simultaneously set which in turn rotates a switching disc 42. The meter 28 is connected 40 with the switching disc 42 through a transmission gear 46 by means of an electromagnetic coupling 4I. During the absorption period the disc 42 Is kept in the position of rest as shown in the drawings so that the movable contact 45 engages 46 the stop 44. Upon the energization of the heating element the kilowatt hour meter 28 comes into engagementwith the disc 42. The latter moves towards the stationary contact 46 opposite to the action of the spring 43. A counter 50 contact 46 is adjustably arranged so that it may be set for the desired amount of energy. When .the contact 45 comes into engagement with the contact 46 the heating element is deenergzed owing to the energization of the circuit-breaking 66 magnet 31 and the coupling 4I is simultaneously released. Consequently, the disc 42 rotates under the action of the spring 43 back to the position of rest shown. To remove the diiliculties which may be presented by a delayed energzation lof the heating element with the aid of the cooling chamber thermostat, it is advisableto also ar-` range in the embodiment shown in Fig. 5 the auxiliary means employed in Fig. 3 or Fig. 4.

It should be understood that I do not limit 66 my invention to the specic arrangements or constructions shown. Many changes in arrangement in construction, particularly when using a gaseous heating agent instead of electric heat, will be obvious to those skilled in the art to which 70 this invention belongs.

I claim as my invention:

l. In a system for heating the generator of an absorption refrigerating apparatus of the intermittent type, an energy source for said generator, 'l5

a line connecting said source with said generator, means inserted in said line for cutting in and out the supply of heating energy to said generator and comprising a clockwork actuated switching mechanism to initiate the supply of heating energy to said generator and a counting mechanism for cutting out the heat supp'y to said generator after a predetermined amount of heating energy has been consumed in said generator.

2. In a system for heating the generator of an absorption refrigerating apparatus of the intermittent type, an energy source for said generator, a line connecting said source with said generator, means inserted in said line for cutting .in and out `the supply of heating .energy to said generator and comprising a clockwork actuated switching mechanism to` initiate the supply of heating energy to said generator and a counting mechanism for cutting out the heat supply to said generator after a predetermined amount of heating energy has been consumed in said generator, and a thermostat inserted in said line to permit a supply of heating energy to said generator at a predetermined temperature.

3. In a system for heating the generator of an absorption refrigerating apparatus of the intermittent type, a cooling chamber, an energy source for said generator, a line connecting said source with said generator,means inserted in said line for cutting' in and out the supply of heating energy to said generator and comprising a switching mechanism to initiate the supply of heating energy Ato said generator and a counting mechanism for cutting out the heat supply to said generator after a predetermined amount of heating energy has been consumed in said generator, and a thermostat in said cooling chamber and inserted in said line being so set as to interrupt the supply of heating energy to said generator upon a decrease of the temperature in said cooling chamber below a predetermined value.

4. In a system for heating a generator of an absorption refrigerating apparatus of the intermittent type, the combination with an energy source for said generator anda line connecting said source with said generator, of means for cutting in and out the supply of the heating energy to said generator and comprising a switchingmechanism to initiate the supply of heating energy to said generator and a heating energy counting mechanism actuated switching disc having a pin arranged thereon, said switching mechanism cooperating with said pin so as to interrupt the supply of heating energy after the disc has rotated a given angle.

5. In a system for heating a generator of an absorption refrigerating apparatus of the intermittent type, the combination with anenergy source for said generator and a line connecting said source with said generator, of means for cutting in and out the supply of the heating energy to said generator and comprising a switching mechanism to initiate the supply of heating energy to said generator and a counting mechanism actuated switching disc having a pin arranged thereon, and a transmission gear so vdisposed between said counting mechanism and said switching disc as to interrupt the supply of heating energy after the disc has been caused Athrough said gear to rotate a given angle.

erator, means inserted in said line for cutting in and out the supply of heating energy to said generator and comprising a switching mechanism to initiate the supply of heating energy to said generator and a counting mechanism for cutting out the heat supply' to said generator 5 after a predetermined amount of heating energy has been consumed in said generator, and heat energy adjusting means including a movable contact and an adjustable counter contact, said movable contact being rotated from its position 10 of rest by said counting mechanism to engage said counter contact.

7 In a system for heating the generator of an absorption refrigerating apparatus of the intermittent type, an energy source for said general5 tor, a line connecting said source with said generator, means inserted in said line for cutting in and out the supply of heating energy to said generator, and comprising a tilting switch to initiate the supply of heating energy to said genera- 20 tor, a heating energy counting mechanism cooperating with said tilting switch so as to cut out the heat supply to said generator after a predetermined amount lof heating energy has been consumed in said generator.

8. In a system for heating a generator of an absorption refrigerating apparatus of the intermittent type, the combination with an energy source for said generator and a line connecting said source with said generator, of means for $0 cutting in and out the supply of the heating energy to said generator and comprising a switching mechanism to initiate the supply of heating energy to said generator and a counting mechanism actuated switching disc and a coupling adapted to engage said counting mechanism with said switching disc upon the operation l of said counting mechanism.

9. In a system for heating the generator of an absorption refrigerating apparatus of the intermittent type, an energy source for said generator, a line connecting said source with said generator, means inserted in'said line for cutting in and out the supply of heating energy to said generator and comprising a switching mechanism for initiating the supply of heating energy to said generator and a counting mechanism for cutting out the heat supply to said generator after a predetermined amount of heating energy has been consumed in said generator and heat energy adjusting means combined with said counting mechanism.

10. In a system for heating the generator of an absorption refrigerating apparatus of the intermittent type, an energy source for said generator, a line connecting said source with said generator, means inserted in said line comprising a tilting switch for initiating the supply of heating energy to said generator, a counting mechanism provided with a switching discr co- 00 operating with said tilting switch so as to cut out the heat supply to said generator after a predetermined amount of heating energy has been consumed in said generator and a clockwork actuated switching disc adapted to switch 05 in said tilting switch.

11. In a system for heating the generator of an absorption refrigerating apparatus of the intermittent type, an energy source for said generator, a line connecting said source with said generator, means inserted in said line, and comprising a tilting switch for initiating the supply of heating energy to said generator, a counting mechanism provided with a switching disc c'ooperating with said tilting switch so as to cut u the action of said spring to the off-position of the tilting switch. y

12. In a system for heating the generator of an absorption refrigerating apparatus of the intermittent type, an energy source for said generator, a line connectingl said source with said generator, means inserted in said line comprising 5 a uiting switch for initiating the supply or heating energy to said generator, a counting mechanism provided with a switching disc cooperating with said tilting switch so as to cut out the heat supply to said generator after a predetermined amount of heating energy has been consumed in said generator and a clockwork actuated switching disc adapted to switch in said tilting switch, said rst named switching disc being provided with a movable stop adapted to render ineiective the action of said counting mechanism actuated switching disc on said switching mechanism at the beginning of the heating period: N

KURT 

